Embodiments of the invention relate generally to conformal coatings and, more particularly, to a method and apparatus for forming a patterned conformal structure for an electrical system.
Technological advancements in the area of electronic devices have experienced vast growth in recent years. For example, while cellular phones are becoming smaller and lighter, their features and capabilities are simultaneously expanding. This has caused an increase in the complexity and operation of the electrical components found in such devices and a decrease in the amount of space available for such components. Several challenges arise from such an increase in complexity of the electrical components and decrease in the amount of space available. For example, based on space limitations, circuit boards are reduced in size to an extent that the routing density for the board may be constrained and limited below a desired amount. As every layer of the circuit board increases the thickness thereof, the number of layers implemented must be controlled and minimized. The reduction in size of the circuit board also leads to increased congestion on the circuit board such that it is difficult to connect component input/output (IO).
The decreased amount of space available also poses a challenge with respect to radio frequency and electromagnetic interference (i.e., RFI and EMI) between components. That is, many electronic components radiate electromagnetic radiation, which may cause interference with other electrical devices. and detrimentally affect the performance and operation of those electrical devices. As a result, shields have been used to prevent such components from causing such interference. The most common RFI/EMI shields are box-type shields comprised of a single piece of folded or stamped metal (i.e., metal cans, metal foil claddings, etc.) contoured to fit over a PC board. Space must be allocated on the circuit board to accommodate these box-type shields, which reduces the space available for other components. That is, conventional box-type shields are bulky and take up a great deal of space and volume, a majority of which is an unused air gap between the circuit board and the shield. This can add to the overall thickness of an electronic device (e.g., a cellular phone). Additionally, a product may have many components requiring RFI/EMI shielding from other components within the product as well as from external sources. Depending on the number of the shields needed, significant weight and cost may be added to the product.
Therefore, it would be desirable to design an interconnect and routing system that decreases routing density and congestion on the circuit board. It is further desired to design a low profile, low weight, high performance RFI/EMI shield that is reduced in size.